UPDATE 2-Sprint profit beats on strong wireless growth

(Adds detail on churn)

Aug 1 (Reuters) - Sprint Corp on Wednesday topped analysts' estimates for quarterly profit, helped by surprise growth in wireless subscribers in a competitive U.S. wireless market.

The fourth-largest U.S. wireless carrier is working to merge with T-Mobile US Inc, in order to combine resources to build the next-generation wireless network, or 5G.

Sprint reported a net 87,000 new phone subscribers who pay a monthly bill during the first quarter, more than double the average analyst estimate of 40,000 additions, according to research firm FactSet.

Shares of the Kansas-based company, which have fallen 9.8 percent this year, rose 2.6 percent to $5.57 before the bell.

Net income attributable to Sprint fell to $176 million, or 4 cents per share, in the three months ended June 30, compared with $206 million, or 5 cents per share, a year earlier.

Analysts expected the company to break even on a per-share basis, according to Thomson Reuters I/B/E/S.

Churn, or the rate of customer defections, was 1.55 percent during the quarter, up from 1.5 percent a year earlier.

In a bid to become the first company to bring 5G technology to major U.S. cities, Sprint has been targeting a first half 2019 launch in at least eight cities, including New York City and Kansas City.

Total operating revenue fell to $8.13 billion from $8.16 billion a year earlier.

(Reporting by Shariq Khan and Vibhuti Sharma in Bengaluru and Sheila Dang in New York; Editing by Anil D'Silva and Nick Zieminski)